Here is the long awaited new 250-cc, four-stroke MX bike from Kawasaki! With significant engine upgrades, improved comfort and superior rider ergonomics, this slender and spirited racer also benefits from less visible but more important revised chassis and suspension components, all for the sake of extra grip, especially out of corners.

Photo: Kawasaki

Looks and attention to details are commendable, including black alumite coating on the rims and fork crowns as well as antifriction coating on the fork tubes. Understated styling and aggressively-shaped body parts contribute to a serious racer look, with the nice and fat Bridgestone knobbies adding to that mean look.

Power and reliability
Based on last year’s KX250X engine but much improved for 2010, the liquid-cooled single-cylinder engine naturally retains the most successful attributes of its predecessor, which famously delivered a generous and steady torque curve across the entire useful rev range. The 2010 version uses a lighter connecting rod and a shorter-skirt piston to reduce rotational energy fluctuations, friction losses against the cylinder wall, and vibrations.

The improved engine operates more freely and builds up revs more frantically, almost on par with the much-appreciated two-stroke engines from yesteryear. The new parts reduce engine braking slightly — further proof that manufacturers are working hard to emulate the happy behavior of two-strokers. In terms of efficiency, a revised ignition mapping also results in quicker throttle response and livelier accelerations.

Black magnesium covers now hide the clutch, ignition system and cylinder head, making for a richer-looking package while helping the engine shed some more weight.

Many more hidden improvements, aimed at increasing durability and reliability, include:
• Electrofusion coating on the cylinder bore for better oil retention and scratch resistance;
• Higher-flow oil pump
• Increased capacity cooling system
• Stainless steel exhaust system, and
• High-absorbing engine mounts to reduce vibrations for the rider

Photo: Kawasaki